Exam 3 clinical cases BIO205

What is the causative agent of Dengue fever?
How is the disease transmitted?ch12

A vector is an organism that carries pathogens and infects other organisms but does notsuffer from the disease.

How are flying arthropod vectors epidemiologically significant?ch12

Flying vectors are more difficult to control because they have broader home ranges thannonflying vectors. Further, some insects migrate and thus invade more areas.

How is the Ebola virus transmitted and what are the symptoms of this disease?ch13

Viruses can replicate only in living cells because they lack ribosomes for synthesizingproteins and enzymes for producing energy and making nucleotides.

How does Ebola virus cause death of blood vessel endothelial cells?ch13

Replication of Ebola virus diverts the host’s resources used to synthesize host protein andRNA molecules. Unable to continue to make molecules required for survival and growth,endothelial cells die. As new virions spread through the body, more endothelial cells die,allowing blood to leak out.

Describe the type of symbiotic relationship between E.coli and the host's intestinal tract. ch14

E. coli is a mutualist—it contributes to good health by creating folic acid, an importantnutrient necessary for production of red blood cells, and vitamin K, which is required fornormal blood clotting. E. coli is also one of the “good” microbiota in the intestine thatprevents overgrowth of pathogens. However, E. coli is an opportunistic pathogen when itspreads to other parts of the body.

What conditions predisposed Nancy to infection with C. difficile?ch14

Nancy is elderly, and our immune systems typically weaken as we age. Another majorfactor related to her disease is the antimicrobial treatment for her sinus infection andsubsequent antimicrobial treatment for the kidney infection. The drugs disrupted thenormal microbiota, creating an opportunity for C. difficile to proliferate.